STAUFF · Replacement Elements · inline line
SF-6721 filter element: specifications & equivalents
The SF-6721 is a STAUFF inline-line hydraulic filter element, sized 128 × 270 mm OD × length. Verify against the current manufacturer data sheet before ordering.
Envelope OD × L 128 × 270 mm
Line type inline
Partially verified. Fit and grade trace to an official interchange document;
dimensional values are compiled from 0 aftermarket listing(s)
and must be confirmed against the manufacturer housing drawing. Confidence score 0.85.
Micron rating, media type, collapse pressure and seal material are not printed in the STAUFF interchange listing and are pending extraction from STAUFF product data sheets. Verify against the current STAUFF catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Filter type | inline line |
| Outside diameter OD | 128 mm |
| Length | 270 mm |
| Integral bypass valve | none (housing/valve-dependent) |
| Source catalog | STAUFF: STAUFF Filter Interchange online database (filterinterchange.com) |
| Last verified | 2026-09-27 |
Sources: STAUFF — STAUFF Filter Interchange online database (filterinterchange.com) — accessed 2026-09-27.
STAUFF® and all model designations are trademarks of their respective owners, used here for identification only — ElementRef is an independent reference site, not an authorized STAUFF distributor.
Dimensions & series range
| Outside diameter | 128 mm (5.039 in) |
| Overall length | 270 mm (10.630 in) |
All 128×270 mm interchange elements →
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
|
↔ 27080011 page in verification queue | UFI | partial | STAUFF Filter Interchange lists 27080011 (VERMEER) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ 3800002 page in verification queue | UFI | partial | STAUFF Filter Interchange lists 3800002 (MICHIGAN FLUID POWER) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ 3800078 page in verification queue | UFI | partial | STAUFF Filter Interchange lists 3800078 (MICHIGAN FLUID POWER) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ 3913002 page in verification queue | UFI | partial | STAUFF Filter Interchange lists 3913002 (FORD) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ 736662 page in verification queue | Aftermarket | partial | STAUFF Filter Interchange lists 736662 (VICKERS) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ 736693 page in verification queue | Aftermarket | partial | STAUFF Filter Interchange lists 736693 (VICKERS) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ 85860 page in verification queue | Aftermarket | partial | STAUFF Filter Interchange lists 85860 (CARQUEST) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ 85865 page in verification queue | Aftermarket | partial | STAUFF Filter Interchange lists 85865 (CARQUEST) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ P779523 page in verification queue | Donaldson | partial | STAUFF Filter Interchange lists P779523 (DONALDSON) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ SP1218 page in verification queue | Aftermarket | partial | STAUFF Filter Interchange lists SP 1218 (ALCO) as replaced by SF-6721. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
Interchange levels: full catalog-confirmed drop-in · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the SF-6721 model number is decoded
- SF-6721STAUFF replacement element part number per the STAUFF Filter Interchange database.
Typical equipment & applications
- Replacement element for OEM hydraulic filter housings
Selection pitfalls — read before you substitute
- “10 µm nominal” and “12 µm at β1000” can describe the very same media — one is reported at β≥200, the other at β≥1000 per ISO 16889. Compare ratings at the same Beta test point, not just the printed micron number.
- Nitrile (NBR) seals are standard for mineral hydraulic oil but fail early in some phosphate-ester fluids and at sustained high temperature; verify seal compound against the fluid data sheet (fluorocarbon/Viton executions may be required).
- End-cap geometry and the number/position of O-rings block interchange even when OD and length match — visually compare end caps before fitting, especially with aftermarket cartridges.
Frequently asked questions
What are the dimensions of the SF-6721 filter element?
The published envelope is 128 mm OD × 270 mm length (5.039 × 10.630 in). Confirm against the housing drawing before ordering.
What replaces the SF-6721 filter element?
10 partial match(es) requiring parameter review
How do I read the SF-6721 part number?
See the designation decoder above: each segment of SF6721 encodes size, line type, filtration grade and media/collapse execution.
Is a same-envelope aftermarket element always a drop-in replacement?
No. Matching OD and length only proves the cartridge fits the bowl. End-cap style, seal compound, micron/Beta rating, collapse pressure and bypass configuration must also match; the table above tags every equivalent as full, partial or verify for exactly this reason.
How often should a hydraulic return-line element be replaced?
Replace at the housing manufacturer’s recommended differential-pressure setting (commonly signalled by a clogging indicator), or on a time-based service interval when no indicator is fitted — never wait for bypass to open continuously, because unfiltered oil then reaches the valves.
Same-envelope elements from other brands
View full interchange →These 3 catalog element(s) share the 128×270 mm envelope. Envelope match alone does not guarantee interchangeability — compare micron/Beta, seals and collapse rating.
Other models in the Replacement Elements series
All 3832 → AD-030-B-125-B AD-030-B-40-B AD-030-B-60-B AD-030-B-80-B AD-030-E-20-B AD-033-B-40-B AD-033-B-60-B AD-033-B-80-B FE-BL-200 FE-BL-500
Reviewed & verified by the ElementRef engineering desk against STAUFF on 2026-09-27. Read our editorial & correction policy.